Synthesis of Novel Kidney-Type Glutaminase Allosteric Inhibitors Targeting the Critical Lys-320 Residue

Jun Song; Chuqiao Pan; Jinxiu Li; Ruisong Bai; Ziying Zeng; Yunying Han; Zhao Chen; Wei Hou; Yong Li; Benfang Helen Ruan

doi:10.1021/acsmedchemlett.2c00302

Synthesis of Novel Kidney-Type Glutaminase Allosteric Inhibitors Targeting the Critical Lys-320 Residue

ACS Med Chem Lett. 2022 Dec 22;14(1):11-17. doi: 10.1021/acsmedchemlett.2c00302. eCollection 2023 Jan 12.

Authors

Jun Song¹, Chuqiao Pan¹, Jinxiu Li¹, Ruisong Bai¹, Ziying Zeng¹, Yunying Han¹, Zhao Chen¹, Wei Hou¹, Yong Li¹, Benfang Helen Ruan¹

Affiliation

¹ College of Pharmaceutical Science, Institute of Drug Development & Chemical Biology (IDD &CB), Collaborative Innovation Center of Yangtza River Delta Region Green Pharmaceuticals, Zhejiang University of Technology, Hangzhou,310014, PR China.

Abstract

Reversible allosteric inhibitors of kidney-type glutaminase (GLS1, KGA) showed incomplete inhibition of cancer cell proliferation and poor in vivo efficacy. Here, we investigate some irreversible inhibitors targeting the critical K320 residue responsible for GLS1 biological activity. The (trifluoromethoxy)phenylacetic acid motif was replaced by α,β-unsaturated carboxylic acids, and the resulting terminally substituted CB839 derivatives (e.g., GJ2 and GJ5) showed good stability in solid form at room temperature, and better liver microsome stability and in vivo pharmacokinetics than coumarin. Both compounds showed binding to the wild-type KGA, whose K _D is 10⁶-fold stronger than that of CB839, but only weak binding to the KGA K320A mutant and no inhibition of GDH proteins. Interestingly, GJ2 treatment significantly decreased the trypsin digestion of KGA, tumor cell clonal formation, and cancer cell growth rate. Taking these results together, targeting the critical K320 residue of GLS1 might be a new strategy to make a potent GLS1 allosteric inhibitor.